Lewis Hamilton believes that Red Bull are capable of a lot more pace than they showed in Friday practice, explaining that he expects Max Verstappen to make a step up in performance on Saturday similar to the old 'quali-mode' engine settings.
Up until last year, teams could use different engine settings for qualifying and the race. Use of performance settings like that are now banned, with teams forced to run the same settings in qualifying and the race. Having beaten Verstappen by two tenths in Friday practice, Hamilton compared the ramp up in performance on Saturday as being similar to the days of such qualifying modes.
"They've definitely got some extra in the bag, I already know that!" Hamilton told media after Friday practice.
"So I think we've made some small progress today. But I think they still, I think they still have the two tenths, maybe it's a tenth and a half or something like that.
"We definitely made some small steps forward but not enough to close that, it's not the two tenths. But over a single lap that felt okay, it felt pretty good. And I just expect them to turn up a little bit more tomorrow, they've almost basically got like the qualifying mode we used to have!
"I asked my guys, I don't understand where they get it from, but it's impressive and we've got to work hard to try and see if we can match them somehow."
With Hamilton topping the times with a lap some 1.2 seconds quicker than he managed in the same session last weekend, the World Champion explained he was happier with the handling of the W12 after having to make setup changes to move closer to what he used at last weekend's race.
"It's been a bit of a struggle in FP1 was a bit of a struggle because I just was trying different variants of the car and the car was unhappy. So then I had to make some more changes back to similar to what I had last week or with some other adjustments and felt much better," he said.
"So, I'm generally happy with where the car is, I'm probably not going to change too much, because most often if it ain't broke, don't fix it most often!
"Most of the time, [if] you always try to eke out more, it gets worse. So it'll be the tiniest of tweaks."
Having returned to Brackley for some sim work after Austria, Hamilton explained that he had tried utilising some of what he learned in the sim at the start of practice, but that it hadn't been successful.
"No, what I learned in the sim is what we started with. And it wasn't good," he admitted.
"So we had to come back on a few changes. There are a couple of things that I've tried at the end, which we were going to test while we're here, but there's just not enough time so that lap..I think that's been a positive.
"Other than that, just in these sessions I've been trying things that I didn't try in the sim."
As for the battle with Red Bull this weekend, Hamilton doesn't expect there to be a huge different in performance between qualifying and the race.
"I'm pretty sure it stays the same, whatever gap they're gonna have tomorrow is usually the gap they seem to have on the Sunday," he said.
"But we'll be pushing up, trying to make that gap as small as possible tomorrow. And we can improve the car tonight and I like to think that our long run was okay. We'll wait and see."
It's time for the latest episode of our new Formula 1 podcast, with F1 journalists Dieter Rencken and Thomas Maher discussing Max Verstappen's ever increasing championship lead, and whether Mercedes can turn things around over the next few races..